The research to be performed during the project period is designed to extend our studies on cerebral asymmetry, emotion and affective disorders. The research is based upon findings which indicate that l. the anterior regions of the two hemispheres are differentially activated during the experience/expression of positive and negative emotions associated with approach and withdrawal behavior respectively; and 2. individual differences in baseline anterior activation asymmetry predict emotional reactivity to affective challenges and are associated with affective and anxiety disorders. The proposed research will examine: brain electrical asymmetries associated with a range of different positive and negative emotions; individual differences in anterior asymmetries in normals and their relation to affective reactivity, personality and mood; anterior and posterior train electrical asymmetries in different sub-types of depressive disorders during the acute stage of illness and in remission; asymmetries in simple phobics prior to and after exposure therapy treatment; the effects of an opiate blocker on brain electrical asymmetries and behavioral manifestations of fear in phobics over the course of exposure therapy; and baseline and task-related asymmetries in young children selected at 30 months of age to be extremely wary and fearful or extremely uninhibited in a longitudinal study. The research proposed offers considerable promise in the identification of patterns of brain activity which index emotions associated with approach and withdrawal and vulnerability to affective and anxiety disorders.